Consumerization of Devices: well known (partially abused) concept: some mobile devices come from the consumer world and hence do not natively offer enterprise class security or suffer from intrinsic vulnerabilities:

Consumerization of Users: many users think they have consumer device so they think they do not deserve enterprise class security measures.

And the risks are:

False Security Perception leads to high probabilities of theft or loss of the device, and most of all, of its data;

Consumerization of Devices leads to vulnerabilities that may be exploited to access and steal sensitive data or authentication credentials;

Consumerization of Users leads the users themselves to adopt imprper habits not appropriate for an enterprise use, which in turn make the device even more vulnerable to malware (i.e. installing non business application, lending it to others, etc.).